The reason the curriculums were like this is that education was largely optional, and so it was designed for the exceptional over-achievers who would voluntarily, with no extrinsic force, opt into such. Now a days education, including tertiary, is designed for anybody with a pulse. And this creates a terrible scenario for overachievers and underachievers alike. The overachievers are bored senseless in lengthy classes because "Yes, I got what you said 40 minutes ago. Why can't we move on?" By contrast the underachievers lack the attention span and focus to follow a 50, let alone 90, minute lesson, so struggle even given the much slower pace.
A 'TikTok-ified' education is really just a desire to stop wasting so much time, but we waste that time because of this change in education. And far from creating a nation of scholars - middling or otherwise, this change has instead just created a nation where your barista probably has a college degree, and 6 figures of debt to show for it.
[1] - https://graphics8.nytimes.com/packages/pdf/education/harvard...